Natural resources provide substantially all of man's energy source materials in the form of fossil fuels, wood and other types of plant life.
Wood and coal have been a principle source of fuel for hundreds of years. Within the last one hundred years, petroleum has become the overwhelming primary commodity for the generation of energy. Petroleum has had the advantages of low cost and ease of transportation and storage because of its liquid consistency. Further, petroleum is readily amenable to fractionation and conversion into a variety of valuable industrial products such as fuels, building products, chemical intermediates, and the like.
Recent international economic developments have signaled the inevitable decline of petroleum as the world's supreme industrial commodity. The price of raw petroleum has increased several fold. Also, the consumption of petroleum has been increasing exponentially, and concomitantly the world petroleum supply has diminished to less than several decades of proven reserves.
Governments and industrial concerns on a priority basis are dedicating increased attention to alternatives to petroleum as sources for fuels and chemical intermediates, i.e., coal and wood. Substantial reserves of coal exist in highly industrialized countries, and wood is both plentiful and replenishable worldwide.
Since most current energy utilization technology requires liquid energy media, it has become an important research and development objective to provide innovative means to convert coal into liquid sources of potential energy.
It was recognized by early workers that coal can be liquified by controlled heating in the substantial absence of oxygen. The conversion products are a liquid and a char. Because of the new compelling economic factors, the technology of coal liquefaction and gasifiation has been expanding at an accelerated pace. Pioneer developments in the field are represented by Lurgi and Fischer-Tropsch techology. More recent advances in coal liquefaction are described in U.S. Pat. Nos.: 1,904,586; 1,955,041; 1,996,009; 2,091,354; 2,174,184; 2,714,086; 3,375,188; 3,379,638; 3,607,718; 3,640,816; 3,642,608; 3,705,092; 3,849,287; 3,870,621; inter alia.
There remains a pressing need for new technology for the conversion of coal into liquid carbonaceous products to complement and to enhance conventional petroleum derived energy applications. Innovative processes for liquefaction of coal are required which are not dependent on high pressure or reducing gases or catalysts for efficient and economic liquefaction of coal.
Accordingly, it is an object of the present invention to provide an improved method for converting solid carbonaceous materials into liquid derivatives having application as fuels.
It is another object of the present invention to provide a process for liquefaction of carbonaceous materials without the use of high pressures or reducing gases or catalysts.
It is another object of the present invention to solubilize coal to form homogenous solutions which are directly applicable as liquid fuels.
It is a further object of the present invention to upgrade low value refractory petroleum residua from refinery operations into liquid fuel media.
Other objects and advantages of the present invention shall become apparent from the accompanying description and examples.